A Quenching and Tempering Treatment Method for Large 34crnimo6 Forgings

A large-scale forging, quenching and tempering treatment technology, applied in the field of heat treatment, can solve the problems of poor oil cooling effect of super-long and super-thick large forgings, inability to ensure stable performance of forgings, hidden dangers of production safety, etc., so as to avoid the phenomenon of quenching oil burning and reduce production Potential safety hazards and the effect of reducing thermal stress

CN106929656BActive Publication Date: 2019-05-07SHANGHAI ELECTRIC SHMP CASTING & FORGING CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2019-05-07

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Abstract

The invention discloses a hardening and tempering method of a large 34CrNiMo6 forged piece. The method is used for processing the large forged piece with the thickness being larger than or equal to 600 mm and the length being larger than or equal to 10,000 mm. The method includes the following steps of (1), quenching, specifically, the forged piece is subjected to quenching and heating with the quenching temperature being 870-880 DEG C; (2), cooling, specifically, a water-cooling and air-cooling alternative manner is adopted to cool the forged piece, and after final cooling, the surface temperature is controlled to be within 250 DEG C; (3), tempering, specifically, the temperature is raised to 590 + / -5 DEG C, and tempering and heat preservation are performed. By means of the method, the cooling and cracking phenomena of the forged piece in the water cooling process can be effectively prevented, and the optimal cooling speed can be obtained; the process is stable and high in reliability, and the performance of the forged piece meets the assessment requirements; and the phenomenon that quenching oil combustion occurs easily when oil cooling is adopted for the large forged piece can be avoided, and potential safety hazards in production are greatly lowered.
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Description

technical field

[0001] The invention relates to a heat treatment method, in particular to a quenching and tempering treatment method for 34CrNiMo6 large shaft parts. Background technique

[0002] The tie rod material used in the 140MN free forging hydraulic press is 34CrNiMo6, the size of the part is: Φ600×22940mm, and the net weight is 40650kg; the forgings require Rm: 800MPa~980MPa after quenching and tempering, Re≥650MPa, A5≥12%, Aku≥28J. The heat treatment size of the forgings is Φ690×23800mm, and the material forgings are ultra-long and ultra-thick forgings (thickness≥600mm, length≥10000mm).

[0003] 34CrNiMo6 is a low-alloy high-strength steel with excellent comprehensive mechanical properties. It is widely used in the manufacture of important parts such as camshafts and connecting rods of engines. It has poor machinability and is generally used in wind power products.

[0004] At present, most of the heat treatment methods for 34CrNiMo6 materials focus on the manufac...

Examples

Embodiment Construction

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0031] Taking 140MN free forging hydraulic press tie rod quenching and tempering as an example, the quenching and tempering treatment method of the present invention is specifically described:

[0032] The material of the tie rod of the 140MN free forging hydraulic press is 34CrNiMo6, the size of the part is: Φ600×22940mm, and the net weight is 40650kg; the forgings require Rm: 800MPa~980MPa after quenching and tempering, Re≥650Mpa, A5≥12%, Aku≥28J. The heat treatment size of the forgings is Φ690×23800mm. Its...